Boiler for steam-heaters



(No Model.) 3 Shets-Sheet. 1.

J. JOHNSON.

BOILER EOE STEAM HEATERS. I No. 338,670. v Patented Mar. 23, 1886.

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(No Model.) 3 sheens -sneet 2. J. JOHNSON.

BOILER FOR sTEAM HEATERS.

No. 338,670. Patented Mar. 23, 1886.

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J. JOHNSON.

BOILER FOR STEAM HEATERS. No. 338,670. Patented Mar. 23, 1886.

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UNITED STATES PATENT OFFICE.

JONATHAN JOHNSON, OF LOWELL, MASSACHUSETTS.

BOILER FOR STEAM-HEATERS.

SPECIFICATION forming part of Letters Patent No. 338,670, dated March23, 1886.

Application filed June 18, 1885. SerlalNo. 169,064. (No model.)

To all whom it may concern:

Be it known that I, JONATHAN J OHNSON, a citizen of the United States,residing at Lowell, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inBoilers for Steam- Heaters; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to theletters and figures of reference marked thereon,which form a part ofthis specification.

This invention relates to certain improvements in that class of boilersemployed for heating purposes by either hot water or steam, and is animprovement on the boilers for which Letters Patent N o. 27 4, 785,dated March 27, 1883, and N 0. 264,835, dated September 19, 1882, havebeen granted.

The improvements relate, principally, to the dome or upper part of theboiler, which, instead of being simply a hollow ring or annulus, as inthe above-named patents,which allowed the products of combustion to passreadily through it, imparting but a small portion of their heat to thewater contained in the ring, in the present boiler consists of a hollowcylinder filled with vertical tubes, as in the ordinary tubular boiler,through which tubes the products of combustion must all pass on theirway to the smoke-stack or chimney, and in their passage necessarilygiving up a large portion of their heat to the water or steam withinthis portion of the boiler.

In order to insure a perfect circulation of water between this dome andthe lower parts of the boiler or water-leg which surrounds the fire-pot,I have arranged circulating pipes which connect the upper and lowerparts of the boilers by a channel outside. Thus removed from theinfluence of the fire, and capable at all times of fulfilling itspurpose by means of this outside eirculation,the contents of the boilerare kept continually in motion, avoiding the danger from deposits ofsediment and incrustation, so injurious to the boilers now in commonuse.

In addition to these improvements, I have devised a band or cover forthe joints of the pipes exposed to the fire, which not only protects thescrew-threads of said pipes from corrosion, but forms a lock-nut thatprevents loosening of the connections by expansion and contractionorother means.

A further improvement is the escape-fine and damper connected with thefeed'door, by means of which a direct draft is made from the door to thechimney when the door is open for the introduction of fuel, thusavoiding the nuisance caused by the exit of smoke or gas through thedoor when the latter is opened.

In the accompanying drawings, Figure 1 is a perspective view of theboiler, a portion of the casing being removed to show the internalarrangement of the parts. Fig. 2 is a vertical section showing therelative positions of the annulus which forms the water-leg surroundingthe fire-pot and the tubular dome and their connecting-pipes. Fig. 3 isa top or plan view illustrating the arrangement of the tubes in the domeand the position of the circulating-pipes outside the casing. Fig. 4 isan enlarged sectional view of one of the connections of thecirculating-pipes, illustrating the construction and arrangement inconnection therewith of the chambered lock-nut or covering-band. Fig. 5shows a modification of the nut, the sleeve being separate from the nutproper,but in contact therewith. Figs. 6 and 7 are enlarged sectionalviews showing the feed-door and damper opened.

In the drawings, A indicates the base upon which the boiler is placed,and which forms the ash-pit below the'grates. This base may be of thesame construction as those used withthe boilers heretofore employed forheating purposes, and illustrated in the patents named. Supported bythis base is the hollow annulus or water-leg B, preferably formed ofcast metal, and of such height as to fully inclose the fuel, thusforming the fire-pot, which is protected from the injurious effect ofthe incandescent fuel by the continuous flow of water through it. Theupper edge of the annulus B is pierced with a series of orifices, whichreceive the lower ends of the vertical tubes at a. These tubes supportand are connected to the lower head of the tubular cylinder or dome O,the space within the tubes and between the dome and fuel forming acombustion-chamber of such size as to insure the thorough mixing andcombustion of the gases cast or wrought metal, as preferred,but in'chimney. It will be apparent that this construction affords a freepassage for the water between the annulus B and the dome through thetubes a a, and also through the latter between the tubes 12 b.

In order to keep up a continuous circul-a tion, thus avoiding thedeposit of sediment in any part of the boiler, I'provide one or morecirculating-pipes, D, which are connected to thewater-leg or annulus Band dome Oby horizontal connections 0 and 0. These connecting pipes ortubes are of such length as to pass through the casing which surroundsthe boiler, whether the same be of metal or brick, so as to bring thevertical pipes 1) out-v side the same. They are therefore beyond thedirect action of the fire, and the water within them is comparativelyquiet, its only movement being that produced by the steady downward flowcaused by the rising of the water within the tubes at, which connect thewaterleg with the dome, the place of which rising water is supplied bythe downward flow above named. I also prefer to continue the pipe Dupward and connect it by a pipe, d, with the.

top of the dome. By this means is afforded an escape downward throughthe pipe D for any water which may rise as foam with the steam when theboiler is used as asteam-heater, and the upper end of said pipe alsoforms a convenient' place for the attachment of the safetyvalve and thepipes which convey steam from the boiler to the radiators. As. thejoints of these various pipes where they are connected to the water-legand dome are exposed more or less to the action of the fire, and arereduced in thickness by the cutting of the screw threads upon them, itbecomes necessary to provide some protection for them at these points,in order to secure them from speedy destruction by corrosion. This Iaccomplish by means of the chambered lock-nuts or sleeves e, theconstruction of which, as shown in Fig. 4, consists of a nut fitting thethread of the pipe upon which it is to be applied, and provided with anextension or sleeve, 6, which is bored out or otherwise so enlarged asto pass over the outside of the thread and pipe. In using thisprotecting-sleeve it is first screwed onto the pipe, which is thenscrewed into an orifice prepared for its reception in the water-leg ordome, packing being interposed between the nut and boiler. The nut isthen turned back until the packing is firmly compressed, thus making aperfectly-tight joint, while the extension or sleeve 6 covers that partof the screw-thread cutin the pipe which would otherwise be exposed.

In the modification shown in Fig. 5 of the drawings the sleeve 6 isshown as separate from the nut, but resting against it. This methodofconstruction allowsthe nut to be screwed up without rotating the sleevewhen the joint is tightened. The boiler is also provided with anautomatically-operating feed-governor, E,

connected with the boiler and water-supply by suitable pipes, saidgovernor not only regulating the height'of the water'in the boiler, butmay also, by means of the connection 9 with the damper which admits airbelow the grate, regulate said admission to correspond with the quantityof water to be evaporated, thus equalizing the amount of fuel consumedwith the steam orheat required. An additional outside pipe, F, isconnected at its lower end to the water-leg and at its upper to the domeabove the water-line. As it is evident that the water within this pipewill always stand quietly at the same height as that within theboiler,not being disturbed by the frequently violent ebullition of thewater in the latter, it follows that the pipe F forms a proper place forthe attachment of the glass gage h and gage-cocks a, the readings fromwhich when so placed being reliable. The upper part of this pipe F alsoforms the place of attachment of the steam-gage k, which is a necessaryaddition to all steam-heating apparatus.

When the apparatus is to be used as a hotwater heater, the plug 12 inthe upper part of the dome is removed and the connection with thecirculating-pipes made at that point, so as to give the full benefit ofthe heat obtained from the tubes b passing through the dome, which is,of course, full of water, as no steamspace is required.

Much difficulty has been experienced from the escape of smoke and gasinto the room occupied by the heater when the feed-door was opened. Toremedy this defect, I employ the devices shown in Fig. 6, in which itwill be observed .that a flue runs from the top of the door, openingdirectly to the smokechamber above the dome. This flue is closed by adamper, m, pivoted in the casing of the door-opening and provided withthe triangular projection n, having an inclined edge, which comes incontact with the lug 0 upon the feed-door L when said door is closed,and which action raises and closes the damper. When the] door is opened,the damper falls, opening the flue and allowing a direct flow of smokeor gas to the chimney from thecombustion-chamber, thus preventing allpossibility of its escape through the door L into the furnace-room. a

The advantage of this apparatus may be summed up in the almost completeprevention of scale and deposit of sediment'within the boiler owing tothe perfect circulation which the great amount of heating-surfaceexposed to the fire causes, the heat in great part being taken up by thecontents of the boiler, allowing but a small portion to escape up thechimney, thus insuring great economy in fuel; and, further, theprotection. afforded by the sleeved lock-nuts to the connecting pipesand joints at the points where they are most-exposed greatly increasesthe durability of the water-line and near the crown-sheet or lower same,rendering frequent repairs unnecessary. head of dome 0, whereby thecirculation will Havingthus described my invention, Iclaim remove allsediment to the lower part of the as new and desire to secure by LettersPatent boiler, avoid incrustation, and generate more I 5 5 thefollowing: steam, substantially as described.

In a boiler for heating or power purposes, In testimony whereof I affixmy signature in the combination of the annulus or water-leg B, presenceof two witnesses. tubular dome 0, vertical tubes at a, and cir- JONATHANJOHNSON. culating-column D, connectingwith the annu- XVitnesses: 1o lusor water-leg by a tube, a, and with the CHARLES H. HOWLAND,

tubular dome by tube 0, entering below the JOHN H. OATES.

